There probably won’t be too many tickets around, as, in those days, single tickets or a half of a return ticket were collected at the end of a journey. At suburban stations the gates were closed as the train pulled into the station and reopened as the train departed, with staff collecting tickets from the arrivals, eg YARRA JUNCTION to RINGWOOD. I can’t remember what happened on arrival at country stations, such as Yarra Junction, as adults held the tickets (a wise decision) for most of my country journeys, including Launching Place. From memory, you could renew periodicals, such as weekly tickets, early by handing in the previous current ticket.
There are online railway memorabilia sites selling groups of Edmondson tickets but the catalogues aren’t detailed enough to locate specific stations and you’d probably have to buy the whole lot anyway. Also, a lot of them are preservation-era tickets rather than Victorian Railways. Someone with experience in this field may be better able to help.
There’s a book Country tickets of the Victorian Railways
. A copy is available for reference at the State Library of Victoria, however that would probably involve a trip to the city.
If you haven’t already done so, perhaps try the Yarra Valley tourist railway at Healesville or similar organisations.
A photo, from Railpage’s Photos section, of a Powelltown Tramway ticket (seems to be paper tram-style, rather than cardboard): https://www.railpage.com.au/photos/134448
(For some reason, the main photo is upside down. The thumbnail below is the correct way round.)